Use this only with Prolog when noting defaulty code, a wordplay combining "default" and "faulty.
When Prolog code needs a default case when everything else fails it is know as being defaulty which is a wordplay combining default and faulty.
Prolog code should not be defaulty!!!
References:
Clean vs. defaulty representations
The cost of defaulty representations
Logic Programming Implementation Part I: The WAM - Scroll down to page 46 to find "Processing a Defaulty Data Structure"
